Hydraulic pump or motor



Sept 10, 1957 J. D. RAMSAY HYDRAULIC PUMP OR MOTOR Filed m. 16, 1954 6 Sheets-Sheet 1 Q Y w mm Q% r M Q m m 0 Q Q M w [Ill 0 o p new ,7 s m m u\ kmrz Sept 10, 1957 J. D. RAMSAY HYDRAULIC PUMP 0R MOTOR .6 Sheets-Sheet 2 Filed Aug. 16, 1954 m w .fl i I I jhm MN- u bv. W \W 7 JW/ A? R. r m, s l. Ma I m -m... MQ wmf MR. HM; I NV NR 7 VPWIIIHIHI N, n l N m mW N \N 1. N \&u

p 1957 J. D. RAMSAY 2,805,548

HYDRAULIC PUMP CR MOTQR Filed Aug. 16, 1954 6 Sheets-Sheet 3 Sept 10, 1957 J. D. RAMSAY 2,805,543

HYDRAULIC PUMP OR MOTOR Filed Aug. 16, 1954 e Sheets-Sheet 4 Sept 10, 1957 J. D. RAMSAY HYDRAULIC PUMP OR MOTOR 6 Sheets-Sheet 5 Filed Aug. 16, 1954 Sept 10, 1957 J. D. RAMsAY 2,305,548

HYDRAULIC PUMP 0R MOTOR Filed Aug. 16, 1954 e'sneets-sh et e Unite tates Patent C) HYDRAULIC PUMP R MGTOR Joseph D. Ramsay, Audubon, .3.

Application August 16, 1954, Serial No. 459,054

QB'Claimst (Cl. 60- 53) This invention relates to a hydraulic pump or motor and more particularly to a hydraulic'pump and-motor combination serving as a hydraulic transmission and having components which move epicyclically. It concerns a device of this kind which operates on the positive displacement principle and in which an infinite range of speed ratios may be attained by appropriate adjustment.

A principal object of the invention has been to provide a hydraulic pump or motor, the displacement of which may be varied within wide limits, which is reversible,v

and which is characterized by high eificiency.

A further object has been to provide a device of this type, in'which slippage is minimized.

Another object has been to provide a device of this type in which a plurality of pump or motor stages are arranged so that vibration forces incident to their operation are minimized and substantial dynamic balance is obtained.

A furtherv object has been to provide a device of this type which may be reversed as desired, and in which this reversal may be accomplished through the same simple control means by which the speed ratio is adjusted.

A further object has been to provide a variable displacement, reversible hydraulic pump and motor combination serving as a hydraulic transmission wherein a pump of the above-stated type cooperates with a motor of similar construction, to give still greater flexibility of control.

A more particular object of the invention is to arrange an epicyclic system comprising a ring, a sun and two equal sized planets, in such a manner that the sun is constrained to move in rotation and translation and the planets roll about the circumference of the sun while engaging the inside surface of the ring, thereby forming two chambers. Eccentric movement of the axis of the sun causes these chambers to enlarge and contract successively so that a pumping action is produced. A corresponding motor portion may be similarly constructed and arranged to transmit power received from the pump portion through a suitable manifold. To minimize vibration that would result from the operation of such a system in its simplest form, 1 position a plurality of epicycloidal stages in phase opposition in such manner that linear and torque forces are effectively cancelled.

The invention resides further in certain structural details hereinafter described and illustrated in the' attached drawings wherein:

Figure l is an assembly view, partly in section and partly in elevation, of a combined pump and motor having twelve systems or stages in three groups separated longitudinally from each other, and each comprising four coplanar systems;

Figure 2 is an enlarged cross-sectional view, taken on the line 2-2 of Figure 3, through the rotor assembly of the first group of coaxial stages, showing the parts in neutral position;

Figure?) is a sectional view taken substantially on the Patented Sept. 10, 1957 Figure 6 is a face view of the second port plate as.

indicated by the line 6-6 of Figure 1;

Figure 7 is a partly diagrammatic cross-sectional view taken substantially on the line 7-7 of Figure 1, showing the rotor assembly of the second group of coplanar stages in eccentric adjustment;

Figure 8 is a face view of the third port plateas indicated by the line 8-8 of Figure 1;

Figure 9 is a partly diagrammatic cross-sectional view taken substantially on the line 9--9 of Figure 1, showing the third group of coplanar stages in eccentric adjust ment;

Figure 10 is a face view of the fourth port plate as indicated by the line 10-10 of Figure 1;

Figure 11 is a view taken substantially on the line 1111 of Figure 10;

Figure 12 is a view taken substantially on the line 1212 of Figure 1;

Figure 13 is a schematic view of the gear system employed in Figure l; and,

Figure 14 is a sectional View of one of the rolling,

Means are provided to constrain the axis of. the sun to move in translation in a circular orbital path eccentric with respect to the chamber at the same time that it rotates on this axis. This eccentric motion of the sun causes the volumes of the compartments to vary. Port plates are disposed at the ends of the chamber to complete the enclosure of the chamber. The ports are disposed in the path of the planets for periodic closure thereby. The internal cylindrical surface preferably takes the form of a ring gear element and the sun and planet components are also geared to prevent slippage therebetween.

While the desired constraint to cause the sun axis to travel in an eccentric circle may be achieved in various ways within the principle of the invention, I prefer to accomplish this by mounting a similar but dilferently staged system in tandem with the first, with the sun gears of the two systems mounted on a common throughrunning shaft, which is universally mounted to permit it to accommodate itself to the constraints imposed by the combination of stages. By appropriate simultaneous adjustment of the positions of the ring gears of the tandem systems, the shaft constituting the axis of both sun gears, when it is rotated on its axis, is caused to describe an orbital circular path of which one circumferential point is at the center of the ring gear of one system and another circumferential point is at the center of the ring gear of the other system. To obtain the greatest degree of dynamic balance and uniform distribution of pulsations I prefer to provide four such systems of coplanar stages in each plane and to mount these at tandem, using three in the illustrated embodiment, although any odd numbergreater than one will produce the desired result.

Dynamic balance is afforded by arranging a plurality. of systems or phases in a plane, in such a manner that: both linear and angular forces are mutually cancelled out. In the embodiment of the invention herein disclosed, four separate systems are disposed at 90 intervals 7 in each plane, with adjacent systems rotating oppositely. For instance, the topmost stage in Figure 2 rotates clockwise, the righthand system of this figure rotates Counterclockwise, the lowermost system rotates clockwise, and' the lefthand system rotates counter-clockwise, therebyeffectively dampening torque reactions. i

In the disclosed emobdiment, provision of three groups" of systems, mounted in tandem and each consisting of four coplanar systems avoids duplication of stage phasef anglesand provides smooth performance. It will be;

they are simultaneously moved in translation about the circumference of the sun gear 12 and within the circumference of the ring gear 16. There will be no pumping of fluid, since there is no change in the volume of the compartments above and below the boundary lines formed by the circumferential surfaces of the planet gears 14 and 15 and the sun gear 12, as the positions'of these chambers change progressively during the travel ofthe planet gears 14 and 15, in their orbitalpath about the sun gear 12.

If, however, the sun gear 12 be made to move in translation, so that its center line no longer coincides with the center line of the ring gear 16, the relative sizes of the upper and lower chambers of the system illustrated at the top of Figure 2 will be changed and pumping action can result. As a further illustration of this point, let us consider the same system discussed above in connection with Figure 2 in connection with a movement in which apparent, for instance that should the number of coplanar groups be four, the stages ofeach group would be phased at 45 intervals and a condition of quadruplication rather than the fullest distribution of phaseangles would result,

with much rougher performance.

With reference to Figure 2 the operation of one system will be described in detail, it being understood that all of the epicyclic systems function in the same manner and. vary only in phase relation. The invention contemplates in its broader aspect the provision of but a single. epicyclic system with means to constrain the sun gear to describe an orbital path as discussed above, although great additional advantages are obtained through the detailed combinations of systems discussed hereinafter.

In the form of the invention used as a pump, as in the topmost stage of Figures 2 and 3, a sun gear 12 is rotated through a universal joint and other driving connections by a splined shaft 13. The sun gear is in mesh with a pair of planet gears 14 and 15, and the planet gears are mounted for free rotation and translation with respect to the sun gear and a surrounding ring gear 16, under the control of the relative rotations and orbital movements discussed hereinafter. The sum-of the diameters of the sun gear and planet gears is equal to the diameter a of the ring gear, with which the planet gears interrnesh internally. The sun :and planet gear elements are preferably of special design to permit them to intermesh properly'while rolling freely upon one another. Thus, the sun gear element may comprise a cylinder 105 as ilustrated in Figure 14, having a splined central aperture 106 for the reception of the drive shaft and annular shoulders 107 at their ends for reception of rings 108 carrying the gear teeth on their outer circumferences. The planet gears may be similarly constructed to provide .complemental gear portions and rolling cylindrical surface faces in the sun and planet members.

Port plates 33 and 34 (Figure 3) are mounted against opposite faces of the casing member 163 in which the ring-carrying element carrying the ring gear 16 is located, and these port plates are provided with passages through which hydraulic fiuid is admitted to the pumping system involving the cylindrical chamber defined at its ends by the port plates, centrally by the sun gear 12, i and divided into two compartments bounded by opposite portions of the ring gear, by the upper and lower circumferential surfaces of planet gears 14 and 15, and the upper and lower circumferential surfaces of the sun gear 12, as illustrated in Figure 2. The inlet passages from the source of supply of hydraulic fluid are interconnected with thehydraulic pump so constituted by a port 17, and the exhaust passages to the point of delivery are interconnected with the pump by a port 18.

With the partsmounted in the position of Figure 2, and the shaft 13 constrained to rotate about its own axis at the center of the ring gear 16, the resulting rotation of the sun gear 12 will cause the planet gears 14 and to rotate without changing their relative positions, 'as

the sun gear 12 not only rotates about its axis as discussed.

above, but in which this axis is itself caused to undergo an orbital movement of translation in a circle from a position in which its center lies at the center of the ring 1 gear 16, as illustrated in Figure 2, through a position in which it lies at some maximum distance from this line,

as illustrated in FigureS;

By reference to Figure 5, it will be seen that the upper chamber defined between exterior surfaces of gears 12, 14

and 15 is much smaller than the lower chamber definedv between these surfaces at the point when ports 17 and 18 are covered by planet gears 14 and 15, i. e., when the sun gear has rotated to its maximum position of eccentricity around the orbital path of its center as indicated by the circle C in Figure 5. The basic feature of the inven-.

tion consists in causing the sun gear axis to describe such an orbital path, thereby causing the chambers above and below the boundaries formed by the circumferences of the gears 14, 12 and 15 to progressively increase or diminish in size as the line joining planet gears 14 and 15 rotates through successive angles of between positions in which both ports 17 and 18 are covered. Thus, as the system rotates while the shaft 13 moves in translation as indicated by circle C from the position at the top -ment B is thus progressively contracted during its movement it impels liquid through discharge port 18, and since upper compartment B is progressively expanded, it draws liquid in through port 17. Thus, the compartments A and B constantly reverse their functions every time the planet gears 14 and 15 rotate through 180 to cover the ports 17 and 18, and the system becomes a double-acting pump, providing one complete impulse every time the line joining the planet gears 14 and 15 rotates through an angle of 180. These facts can be demonstrated by reference to fairly simple geometrical principles.

The motion of the sun gear axis in translation about the circle C during rotation of the sun. gear about this axis may be imparted by any means available-to the skill of the tart within the principles of the invention, so long as lit is properly coordinated with the gearing and they rotation imparted to shaft 13. However, it is preferably accomplished by combination of the system illustrated in Figures 2 and 5 with that illustrated in Figure 7, through a relatively simple adjustment. For understanding of this, please refer now to Figure 7. This figure, like Figure 5, shows a coplanar group of four systems, which cooperate in a combination discussed hereinafter in. an

gen sis- '5 advanced form of the pump, but it may be understood in its simpler form by consideration of the uppermost system alone. This is identical with the system S of Figures 2 and 5 in its elements, and has its sun gear 19 mounted in line with sun gear 12 of Figures 2 and 5, and keyed to the same shaft 13. Any movement of translation of shaft 13 therefore causes similar movement of sun gears 12 and 19, land planet gears 14 and 15 of system S (Figures 2 and 5) and planet gears and 21 (Figure 7-) of system S accommodate themselves through movements of rotation and translation to any such movement, so long as ring gears 16 and 22 remain stationary. If, on the other hand, ring gears 16 and 22 are moved in directions at right angles to their common axis from the concentric position of Figure 2, this same kind of accommodation will also occur.

The ringcarrying element 10 (Figures 2 and 5) is mounted for limited movement in casing 163 for adjustment of the relation of sun gear 12 and shaft 13 to the ring gear 16 cm'ed within ring-carrying element 10. To this end, ring-carrying element 10 has tang projections 23 at its upper and lower ends, as illustrated, and these are slidably received within slots 24 within the upper and lower sides of casing 163, so that by appropriate adjustment of element 113, the position of this element within casing 163 may be lowered from the position of Figure 2 to the position of Figure 5, or moved in an opposite direction to move the upper tang 23 upwardly within its slot 24. This relative vertical adjustment is achieved by a Q8111 or eccentric 25 keyed to a cam shaft 26 and acting through needle bearings and an eccentric ring on wear plates carried within a central opening in element 10, to raise or lower the same. By inspection of Figure 2, it will be seen that this figure illustrates a neutral intermediate position of adjustment of element 10 within oasing 163, and that Figure 5 shows the lowermost position of adjustment attained by rotation of cam 25 counterclockwise from Figure 2 by 90. Rotation of cam 25 clockwise through 90 will give the uppermost adjustment position, while rotation in either direction through various intermediate anges between 0 and 90 will give any desired intermediate position of adjustment.

Ring-carryin g element 27 in which the systems of Figure 7 are mounted has tangs 28 received in slots 29 of its casing 30 arranged at an angle to the corresponding parts of Figures 2 and 5, in this case 120 apart in a clockwise direction. Cam shaft 26 carries a cam 31 (Figure 7), which is mounted and designed to produce movement of element 27 in casing 30 which is identical with that produced by cam 26 on casing .10, except that it is in a different direction, 120 removed, as illustrated. Thus, when the cam shaft 26 is in the position of Figure 2, the ring-carrying element of the system S (Figures 2 and 5), the system S (Figure 7) and each of the other ten pumping systems to be discussed hereinafter, are in their neutral positions, where no pumping will occur when their sun gear shafts 13 are driven to provide the epicyclic motion. Movement of the cam shaft 13 to any other position of adjustment will, however, cause each of these systems to act as a pump to pump liquid in one direction or the other, the direction and rate of pumping being dependent on the direction and magnitude of adjustment from the neutral position.

The phasing of the pumping action of system S of Figure 7 is also dilferent from that of the system S of Figures 2 and S, in this case following it by 60. This relationship is achieved by the initial setting of the diametrically opposed planet gears into the desired angular relationship to the inlet and discharge ports, as they retain the desired phase relationship once properly assembled. By comparison of Figures 5 and 7 it will be seen that when the system S is at the position where planet gears 14 and 15 cover inlet port 17 and discharge port 18 (Figure 5) marking completion of a pumping impulse, the line joining the centers of planet gears 20 and 21 '6 has 60 of angle to traverse before their pumping impulse is completed by coverage of inlet port 32 by planet gear 21 and discharge port 35 by planet gear 20. Let us assume now that the parts so far described have been assembled in the neutral adjustment position of Figure 2, with the sun gears and ports bearing the' relative positions of Figures 5 and 7. Now, when cam shaft 26 is rotated through to its extreme forward pumping position as illustrated, this will produce relative movements of translation and rotation between the sun gears and their associated planet gears to adjust them to the changed positions illustrated in Figures 5 and 7. The reason for the adjustment to these changed positions may be explained by the following geometric considerations. If the center of the ring gear of system S is moved a small distance downward in a vertical direction from the neutral adjustment position of Figure 2 while shaft 13 is held against rotation, the only possible motion of sun gear 12 is one of translation along a line through the center of the ring gear of system S at right angles to a center line between planets 14 and 15, which in this instance is a vertical line (see Figure 5). Now, at the same time, the center of the ring gear of system S (Figure 7) is moved upward to the left from the neutral adjustment position at an angle of 60 from the vertical, and the only possible motion of sun gear 19 in this adjustment, remembering that shaft 13 is not rotated, is one of trans lation along a line through the center of the ring gear of system S at right angles to a center line between planets 20 and 21. This is :a line upward at an angle of 60 to the right of the vertical. The fact that any movement of sun gears 12 and 19 in the assumed adjustment of systems S and S must be at right angles to the center lines joining their respective planet gears follows from the fact that shaft 13 is held against rotation during this adjustment, and that equal but opposite rotary movements are accordingly imparted to the planet gears associated with the respective su-n gears. Finally, the only possible position that shaft 13 carrying sun gears 12 and 19 can assume while satisfying both the requirements of intersecting a line perpendicular to the center line between planets 14 and 15 and a line perpendicular to the center line between planet 20 and 21 is that illustrated in Figures 5 and 7. The movement of the systems from the concentric arrangement of Figure 2 to the eccentric arrangements of Figures 5 and 7 follows naturally from adjustment of shaft 26 through an arc of 90 as illustrated, since shaft 13 although universally mounted, is prevented from moving downwardly in response to movement of cam 25 (Figure 5) by its confinement in the system of Figure 7, [and is prevented from moving diagonally upwardly in response to movement of cam 31 (Figure 7) by its confinement in the system of Figure 5, except under the mutual. constraints imposed by these two systems.

In the ensuing rotation of shaft 13 through its universal joint, planets 14 and 15 of Figure 5 will be rotated and simultaneously moved in translation in a clockwise direction, and planets 20 and 21 will also undergo a similar simultaneous .rotative and translatory movement. However, due to the mutual restraints discussed above, the center of shaft 13 must always intersect a line drawn through the center of ring gear system S perpendicular to the center line 1415 (Figure 5) land a line drawn through the center of system S perpendicular to the center line 2021 (Figure 7). The locus of this line which defines the successive positions of the center of the shaft 13 as power is applied thereto is the circumferential surface of the cylinder represented by the circles c in Figures 5 and 7, and the pumping action of the system results from this eccentric motion.

In the immediately foregoing discussion, it has been assumed that shaft 13 is held against rotation during adjustment of the cams through shaft 26. As pointed out hereinafter, the shaft 13 is not necessarily held against such rotation, as adjustment may be made during application of power to rotate that shaft. However, the prin-' ciples discussed above are equally applicable regardless of such rotation, as the position of the shaft 13 attained at the end of the adjustment will be upon the arc of the circles c, and the subsequent movement of the shaft center will be around that arc. The controlling factor is, as discussed above, that this position is intersected by lines extending centrally through systems S and S at right angles to the lines joining their respective planet gears at the instant the adjustment is completed, and the locus of all of these positions is the circle 0, for the extreme adjustment illustrated, and smaller circles for less drastic adjustments.

Thus, when power is applied to shaft 13 through universal joint 36 (Figure 1) to rotate the same, this will produce movement of the planet gears about the interior of the ring gears and simultaneous movement of the axis of shaft 13, which is also the axis of both of sun gears 12 and 19, about a circular orbit C (Figures 5 and 7) whose extreme point of eccentricity with regard to each ring gear is reached at the part of the cycle when the inlet and exhaust ports are covered, and whose path coincides with the center of the ringgear when the line joining the planet gears is at right angles to the line joining the ports. It will be seen that these conditions are the necessary results of the constraints imposed by the organization of elements as discussed above and that they result, as above indicated, in one complete pumping impulse in each system for each movement of the common axis of the sun gears through the orbit C.

From the foregoing, it will be seen that the amount of iquid pumped duning each impulse may be adjusted from zero to a maximum by corresponding adjustment of cam shaft 25 in a counterclockwise adjustment. To reverse the direction of flow it is only necessary to move this shaft in a clockwise direction, thereby reversing the functions of the inlet and discharge ports.

In the preferred form of the invention, the combination of stages or systems is amplified to produce static and dynamic balance and to provide exceptional smoothness of liquid flow. There is provided a third system S" (Figure 9), identical with systems S and S and likewise operating from shaft 13 for rotation of the sun gear and from cam shaft 26 for adjustment of its cam, which causes movement of ring-carrying element 37 in a direction 120 removed from that given to both of ring-carrying elements it) and 27 of systems S and S. To produce balanced operation, there is contained within each ringcarrying element 1% 27 and 37, four separate but identical coplanar systems, spaced 90 apart, with alternate sun gear driving shafts rotating at the same speed but in opposite directions. necting the inlet and discharge ports of each system are in a line at right angles to the direction of adjustment of the ring-carrying plate of that system by its corresponding cam. By providing an odd number of coplanar foursystem groups, with uniform timing of the phase angles between the individual systems, there may be obtained twelve uniform impulses for each rotation of the individual sun gear shafts in a system having three coplanar groups, twenty regular impulses with five coplanar groups, etc. If, on the other hand, an even number of coplanar groups is provided, it is impossible to avoid duplication of phase angles, and the action will be more sporadic. For example, if four coplanar groups be provided, there can be only four separate evenly timed impulses, since each system in a coplanar group is interconnected with corresponding systems operating from the same sun gear shaft in the other coplanar groups.

The tuning of the systems is graphically illustrated in thedrawing, where the simultaneous positions of the systems are illustrated in Figures 5, 7 and 9. The line joining the inlet and discharge ports is in every case regarded as the zero angle, for a pumping impulse has just been completed and a new impulse is about to begin as the it will be noted that the lines conin Figure 5. By reference to Figure 5, it will be seen that. the sun gears of the system S are at zero angle,

while the next clockwise system S2 is at 135 having 45 1 to traverse until discharge port 38 and inlet port 39 are again covered. System S3 is at having 90 to traverse before discharge port 40 and inlet port 41 are covered, and system S4 is at 45, having of angle to traverse to complete its cycle of discharge of liquid through port 42 while receiving it through port 43. In

this connection 'it is to be noted that the relative positions of. the inlet and discharge ports are reversed for the counter-clockwise rotating systems S2, S4, S'2, S-4,

S2, and S"4, as compared to the systems S, 8-3, 8',

S'3, S and S3, which rotate clockwise; Thus, the

ports 13, 41 (Figure 5), 35, 44 (Figure 7), and 45 and.

46 (Fi ure 9) ofsystems S, S3, S, S3, S" and.S"3 are discharge ports, while their opposite ports 17, 41,32,

47, 48 and 49 are inlet ports, while on the other hand Since the individual epicyclic systems are identical in every particular except for phasing, location of ports, and directions of rotation, as discussed above, having gears and cams of the same dimensions and driving connections to drive the sun gears at the same speeds, this same timing of phases will be maintained throughout the operation of the pump, and the phase angles between the systems will always differ by the same [amounts indicated in the above table, as the systems rotate.

To provide a ducting and fluid flow system supplying liquid to the group of twelve individual impeller systems comprising the complete pump discussed above, the assembly includes casing members 163, 30, and 59 housing the coplanar systems of Figures 7 and 9, and port plates 33, 34, 60 and 61 for guiding liquid from the common supply duct into the inlet ports and from the discharge ports into the common discharge duct of the pump. All of these parts, as well as the corresponding parts of the motor M associated with the pump, are held in assembled relationship with each other and with end housing members by through-running tie rods 62 (Figure 3) and nuts 63.

As shown in Figure 4, port plate 33 is provided with the inlet and discharge ports 17 and 18 for system S, 39 and 38 for system S2, 41 and 46 for system S3 and 43 and 42 for system S-4. Similarly port plate 34 of Figure 6 carries on its surface facing casing 35?, inlet and discharge ports 32 and 35 for system S, 54 and 5t? for system S'2, 47 and 44 for system S3 and 55 and 573. for system S-4. On its opposite face, facing casing 163 and port plate 33, it is provided with inlet and discharge ports 17 and 18, 39 and 38, 41 and 40, and 43 and corresponding in position and function to the correspondingly numbered ports in plate 33.

Port plate 60 of Figure 8 carries ports 48 and 45, 56 and 52, 49 and 46, and 57 and 53, serving as inlet and discharge ports to the system S", and it also carries in its opposite face inlet and discharge ports 32 and 35, 54 and 5t 47 and 44 and 55 and 51, facing the corresponding ports of port plate 34, and serving with these ports as inlet and discharge ports for the S systems.

Port plate 61 of Figure 10 carries ports 48 and 45, 56

and 52, 49. and46 and 57 and 53, facing corresponding 9 ports of plate 60 and serving with them as inlet and dis charge ports to the systems S", and it also carries in its opposite face ports for inlet and discharge of fluid from the first set of coaxial systems of the motor section, as discussed hereinafter.

By reference to Figures 2, 4, 5, 6, 7, 8 '9, and 12, it will be seen that arcuate spaces 64 and 65 are formed on diametrically opposite ends of each port plate 33, 34, 60 and 61 between casing elements 163, 30 and 59 and their respective ring-carrying elements 10, 27, and 37, and these spaces form continuous but irregular passages for supplying liquid to the inlet ports and receiving it from the discharge ports, with the apparatus assembled as indicated. In the operation of the pump as a part of a transmission, these supply and discharge passages are maintained filled with oil under some degree of pressure at all times.

By reference to Figures 4, 6, 8 and 10, it will be seen that supply passage 64 communicates with inlet ports 17, 39, 43, 41, 32, 54, 47, 55, 48, 56, 49, and 57 through channels 66, 67, 68, 69, 70, 71, 72, .73, 74 and 75 formed in the port plate faces, and the discharge ports communicate with discharge passage 65 through similar channels. Liquid is thus pumped in twelve systems arranged in parallel with phase separation continuously from channel 64 into channel 65 during the operation of the pump.

When the pump is used as the impeller of a hydraulic transmission, as illustrated, this liquid is continuously passed to the inlet of a suitable hydraulic motor in motor section M. As here illustrated, this motor may take the same form as the pump, comprising twelve motor units or systems, providing torque multiplication because of their larger capacity. These are arranged in parallel for feed impulses at regular 15 phase intervals. The inlet ports of the motor section port plates communicate with discharge passage 65 of the pump section and the discharge ports of the motor section communicate with the supply passage 64 of the pump section, so that a complete cyclic flow of fluid occurs between pump and motor sections during transmission of power from the power source to the pump, thence to the motor and thence to the power outlet.

The end port plate 61 (Figure 10) of the pump section also serves as the port plate for the first set of four coplanar systems of the motor section, inlet ports 75, 76, 77 and 78 of this motor section communicating with discharge passage 65 and discharge channels 79, 80 and 81 of the port plate, while discharge ports 82, 83, 84 and S5 of the motor section communicate with pump section supply passage 64 and pump inlet channels 73, 74 and 122 of the port plate. a

It will be seen from the foregoing discussion of the portion of port plate 61 which serves to supply liquid to the first four coplanar systems of the motor sections that these are not only similar to the arrangements in the pump section, but their location is actually identical to the systems illustrated in Figures 2 and 5. The motor section may, therefore, be regarded as identical (except for widths), element for element, with the pump section as discussed above, even insofar as phasing and arrangement of port plates in the successive groups of systems S, S, and S" are concerned. It will, therefore, be evident that the end port plate 109 of the motor section has inlet ports arranged in the same pattern with respect to its supply passage 65 and discharge ports arranged in the same pattern with respect to its discharge passage 64, as the arrangements of the inlet and discharge passages for the last pump systems S", except that the supply passage of the pump section has become the discharge passage of the motor section, and vice versa. Therefore, in Figure 12, the inlet ports 110, 111', 112 and 113 will receive liquid from the supply passage 65 through channels 114 and 115, while the discharge ports 116, 117, 118 and 119 will discharge it through channels 120 and 121 into discharge passage 64 whence it is returned to the inlet passages of the pump. Thus, the pump and motor combination may comprise an arrangementin which the pattern of passages, channels, ports and planet gear arrangements is identical, system for system, in the pump and the motor.

From the foregoing discussion, it is believed that the operation of the pump and motor combination in transmission of power will be clear. For an illustration of how this is accomplished, reference should now be made to Figures 1 and 13.

The drive shaft 86 is journalled in bearings 88 and receives power from any suitable source, for example from an internal combustion motor. A ring gear 87 and spur gear 89 are secured for rotation with shaft 86, and these gears mesh with the gears which drive the individual sun gear shafts. Thus the ring gear 87 meshes with a spur gear 90 mounted on a shaft 91' journalled in bearings 92 to drive sun gear shaft 93 and its associated group of three tandem epicycloid pumping systems through universal joint 94, while spur gear 89 meshes with another spur gear 95 mounted on shaft 96 journalled in bearings 97 to drive one of the oppositely rotating sun gear shafts, which may be the shaft 13 driven through universal joint 36 to activate the three systems S, S, and S". The gears 90 and 95 are mounted at positions about the shaft 86 which are 90 removed from each other, and another spur gear (not shown) similar to 90 meshes with the ring gear 87 at a point 180 removed from the gear 90, while still another spur gear (not shown) similar to 95 meshes with spur gear 89 at a point 180 removed from gear 95. These two furthergears carry shaft and universal joint connections to the remaining two sun gear shafts, so that the shafts of systems S, S3, S, S3, S" and S"-3 rotate at equal speeds but in opposite directions to those of systems 8-2, 8-4, S'-2, S'4, S"-2 and S"-4, as discussed above. A system of shafts and gears sim ilar to that used to provide power to the impeller systems comprising the twelve pumping units, as discussed above, is employed to transmit power from twelve motor units to the output shaft 96.

The operation of the pump and motor for transmission of power will be evident from the above discussion. With the epicyclic systems in the neutral positions of Figure 2, and power applied through input shaft 86 to rotate sun gear shafts 13, 93, etc., the planet gears 14, 15, 20, 21 etc., will move in their orbits without change in their relative positions, so that no pumping occurs. If pumping with maximum displacement from space 64 to space is desired, cam shaft 26 is adjusted by rotation a full 90 in the counter-clockwise direction from the position of Figure 2 to the position of Figure 5. If full pumping in the opposite direction is desired, as when it is desired to reverse the direction of movement in use of the device as a transmission, the shaft is rotated 90 in a clockwise direction, thereby reversing the functions of the inlet and discharge ports and channels. If less than full pumping is desired, the adjustment is made by rotation through only a part of one of these 90 arcs, thereby obtaining control of the degree of speed reduction. When power is applied to rotate shaft 86 with the cam shaft rotated to any position of eccentric adjustment, this will cause alternate changes in size of the opposite chambers into which each epicyclic system is divided, and pumping will occur.

The motor section may be similarly adjusted to give an infinite variety of speed ratio variation between pump input shaft 86 and motor output shaft 96. If the pump is made reversible, however, there will be no occasion to make the motor also reversible so long as the two are used together in a hydraulic transmission combination. Hence,

the cam shaft of the motor will ordinarily be operated only through an angle of i. e., from its neutral position to the position of extreme eccentricity for forward driving.

The adjustment of the cams which control the capacities and speed ratios of the pump and motor maybe ac-" complished manually, by motor means, or by some form of automatic combination. In the drawing, I have shown' a suitable form of pilot motor 97 driving a chain 93 for rotating worm 102 and worm wheel 103 (Figure 3) to turn the shaft 26 to a desired position of adjustment, and a similar combination of motor 99 and chain ldt) serves for adjustment of the position of the corresponding shaft mounting thecams which control motor capacity adjustment. An opening 101 is providedin the top for filling the apparatus comprising the pump and hydraulic motor with liquid, and this is normally connected to an external source in such a way as to maintain all of the liquid within the system under at least some degree of positive pressure. When desired, liquid may be drained from the system through an outlet 16%.

As a particular instance to use of the transmission in driving a motor vehicle, the cam which adjusts the positions of the ring gear mountings of the motor unit will ordinarily be in its position of maximum eccentricity adjustment, thereby providing maximum displacement of liquid incident to drive of the shaft 96. When the vehicle is at rest, the cam shaft of the pump section will be in the position illustrated in Figure 2, i. e., in neutral. To start the vehicle in forward or reverse motion, this cam shaft 26 will be moved to a position of slight eccentric adjustment, and as the vehicle speed ratio is to be increased, this eccentricity of adjustment will be increased more and more, until the maximum position of eccentricity is reached. Further increase in the speed ratio, to put the vehicle into still higher gear, so to speak, may

'then be attained by rotating the cam shaft of the motor section to a position of less than its full eccentricity, and progressively decreasing this eccentricity as the speed ratio is to be still further increased. By adjusting the cam shaft in this sequence, either manually, semi-automatically, or fully automatically, the speed ratio may be varied to an infinite degree, as desired. Persons skilled in the art will be aware that a variety of automations may be adapted to the sequential controls of the motors 97 and 99, as discussed above, to eflect the degree of adjustment desired based on accelerator position, manifold pressure, engine speed, or various combinations of these, through first adjusting motor 97 to its maximum limit of cam shaft eccentricity, and then applying further adjustment to the motor 99 to positions of smaller eccentricity as the speed ratio is to be changed to a still higher gear. The reverse sequence will of course be followed for adjustment in the opposite sense.

While the invention has been described with reference to a particular illustrative embodiment, I wish it to be understood that it is to be limited in interpretation only by the scope of the following claims, as various refinements and modifications are evidently available to those skilled in the art.

I claim:

1. In a hydraulic pump or motor, the combination comprising a chamber having end walls, a circumferential wall forming the inner surface of a ring gear member, and walls dividing said chamber into two separate compartments, said last-mentioned walls being the circumferential surfaces of a sun gear member and two planet gear members intermeshed with the ring gear member and said sun gear member, means to apply power to effect rotation of said system of sun gear and planet gear members, and means for constraining said sun gear member to move eccentrically relatively to said ring gear member, upon application of said power, whereby to change the relative positions of said planet gear members according to a predetermined cycle, and thereby change the relative positions of said last-mentioned walls to vary the volumes of said two separate compartments according to a predetermined pattern, and'means for alternately admitting liquid to and discharging liquid in timed relation to said faces of a sun gear member and two planet gear members intermeshed with the ring gear member and sun gear member, means for constraining said sun gear member to move eccentrically relatively to said ring gear memer upon rotation of said sungear member to change the" relative positions of planet gear members according to a predetermined cycle, and thereby change the relative positions of said last-mentioned walls to vary the volumes of said two separate compartments according to a prede termined pattern, means for alternately admitting liquid to and discharging liquid from each of said compartments in timed relation to said volume changes, and means to apply power to said gun gear member to rotate the same to effect said pumping action; said motor comprising a chamber, end walls, a ring gear member, a sun gear member, planetrgear'members and means for admitting and discharging liquid interrelated in the same arrangement defined-above for said pump, and means interconnected with the sun gear member of said motor for transmitting power to a power outlet.

3. In a hydraulic pump or motor, the combination comprising a chamber having end walls, a circumferential wall forming the inner surface of a ring gear mem ber, and walls dividing said chamber into two separate compartments, said last-mentioned walls being the circumferential surfaces of a sun gear member and two planet gear members intermeshed with the ring gear member and said sun gear member, and the sum of the diameters of the sun gear member and the two planet gear members being substantially equal to the diameter of the ring gear member, means for moving the axis of said sun gear member relatively to the axis of said ring gear member, through a circular orbit eccentric to said ring gear member and simultaneously applying power to elfect rotation of said sun gear member on its axis, whereby to change the relative positions of said planet gear members according to a predetermined cycle, and thereby change the relative positions of said lastmentioned walls to vary the volumes of said two separate compartments according to a predetermined pattern, and means for alternately admitting liquid to and discharging liquid from each of said compartments in timed relation to said volume changes.

4. In a hydraulic pump or motor, the combination comprising a pair of chambers each having end Walls, a circumferential wall forming the inner surface of a ring gear member, and walls dividing said chamber into two separate compartments, said last-mentioned walls being the circumferential surfaces of a sun gear mem ber and two planet gear members intermeshedrwith the ring gear member and said sun gear member, the sun gear members being mounted upon a common universally mounted shaft, and the ring gear members being mounted for eccentric adjustment with respect to each other, means to apply power to elfect rotation of said system of sun gear and planet gear members, and thereby move said sun gear members eccentrically relatively to their respective ring gear members upon application of said power, whereby to change the relative positions of said planet gear members according to a predeterminedcycle, and thereby change the relative positionsof said lastvolumes of said two separate compartments comprising 13 each of said chambers according to a predetermined pattern, and means for alternately admitting liquid to and discharging liquid from each of said compartments in timed relation to said volume changes.

5. In a hydraulic pump or motor, the combination comprising a plurality of chambers each having end walls, a circumferential wall forming the inner surface of a ring gear member, and walls dividing said chamber into two separate compartments, said last-mentioned walls being the circumferential surfaces of a sun gear member and two planet gear members intermeshed with the ring gear member and said sun gear member, the sun gear members being mounted upon a common universally mounted shaft, and the ring gear members being mounted for eccentric adjustment with respect to each other, means to apply power to efiect rotation of said system of sun gear and planet gear members, and thereby move said sun gear members eccentrically relatively to their respective ring gear members upon application of said power, whereby to change the relative positions of said planet gear members according to a predetermined cycle, and thereby change the relative positions of said last-mentioned walls in each of said chambers to vary the volumes of said two separate compartments comprising each of said chambers according to a predetermined pattern, and means for alternately admitting liquid to and discharging liquid from each of said compartments in timed relation to said volume changes.

6. A combination as defined in claim 5, in which each chamber is a part of a coplanar group of epicyclic systems of which each group includes four separate systems of sun gears and ring and planet gears as therein defined.

7. A combination as defined in claim 5, in which each chamber is a part of a coplanar group of epicyclic systems of which each group includes four separate systems of sun gears and ring and planet gears as therein defined, and in which the plurality of systems mounted on each common axis is an odd number greater than one.

8. A combination as defined in claim 5, including means for adjusting the degree of eccentricity of the respective ring gears relatively to each other simultaneously and equally, but in different directions.

9. The combination as defined in claim including means for adjusting the eccentricity of the respective ring gears relatively to the sun gears in opposite directions and thereby providing choice between forward and reverse driving of the apparatus.

10. In a hydraulic pump or motor, the combination comprising walls defining a chamber, some of said walls having a plurality of ports, sun and planet gear members forming an epicyclic system with the inner surface of a ring gear member forming a circumferential wall of the chamber wherein the sun and planet assembly forms a barrier dividing the chamber into two compartments, said sun gear member being operable upon actuation to roll the planet gear members over the said inner surface of the ring gear member, means for constraining said sun gear member so that the axis thereof describes a circular path eccentric to said ring gear member but intersecting the axis thereof so that as the eccentricity of the position of said sun gear member increases the barrier formed by said epicyclic system causes said compartments to vary in volume, said ports being positioned to supply hydraulic fluid to the compartment increasing in volume and to discharge fluid from the compartment decreasing in volume.

11. In a hydraulic pump or motor, the combination comprising a wall having an inner ring gear member surface and opposed end plate surfaces defining a chamber, said end plates having a plurality of ports, sun and planet gear members forming an epicyclic system with the inner ring gear member surface wherein the sun and planet assembly forms a barrier dividing the chamber into two compartments, said sun gear member being operable upon actuation to roll the planet gear members over the 1'4 interior of said ring gear member, means'for constraining said sun gear member so that the axis thereof describes a circular path eccentric to said ring gear member but having one point intersecting the axis of said ring so that as the eccentric position of said sun gear member increases the barrier formed by said epicyclic system causes said compartments to vary in volume, said ports being positioned to supply hydraulic fluid to the compartment increasing in volume and to discharge fluid from'the compartment decreasing in volume.

12. In a hydraulic pump or motor, the combination comprising a ring gear member and opposed end plates defining a chamber, said end plates having a pair of spaced ports, sun and planet gear members forming an epicyclic system with the inner ring gear member surface wherein the sun and planet assembly forms a barrier dividing the chamber into two compartments, said sun gear member being operable upon actuation to roll the planet gear members over the said inner ring gear member surface, means operable upon actuation to displace said ring gear member with respect to said end plates in a direction perpendicular to the line joining said ports, means for constraining said sun gear member so that the axis thereof moves about a circle eccentric to said chamber but having one point intersecting the axis of said chamber so that as the eccentric position of said sun increases, the barrier formed by said epicyclic assembly causes said compartments to vary in volume, said ports being positioned to supply hydraulic fluid to the compartment increasing in volume and to discharge fluid from the compartment decreasing in volume.

13. In a hydraulic pump or motor, the combination comprising a movable ring and stationary end plates defining a cylindrical chamber, each of said end plates having a plurality of spaced ports, sun and planet components forming an epicyclic system with the inner cylindrical surface of the chamber wherein the sun and planet assembly forms a barrier dividing the chamber into two compartments, said sun component being operable upon actuation to roll the planet components over the said inner cylindrical surface, means efiective to displace said ring with respect to said end plates, means for constraining said sun so that the axis thereof describes a circular path eccentric to said chamber but having one point intersecting the axis of said chamber and so that the ports are covered by the planets when the sun is in an eccentric position and subsequent movement of the sun varies said compartments volumetrically and effects uncovering of the ports so that some of said ports become intake ports and the others of said ports become discharge ports.

14. In a hydraulic pump or motor, the combination comprising an epicyclic gear system comprising an internal gear, a sun gear, and a pair of planet gears each engaged with the internal gear and the sun gear, casing means forming with the internal gear, a cylindrical chamber enclosing the sun and planet gear assembly, said assembly forming a barrier dividing the said chamber into two compartments, means for rotating the gears to cause the sun and planet assembly to revolve in the chamber, means for constraining the sun gear to move in an orbital path eccentric with respect to the internal gear, and port means in the wall of said chamber including separate port elements communicating respectively with said compartments.

15. In a hydraulic pump or motor, the combination according to claim 12 wherein the ports are located individually at an end of the chamber in the path of the planet gears arranged for simultaneous registration with and periodic closure by the respective planet gears.

16. In a hydraulic pump or motor, the combination comprising a wall having an inner cylindrical surface and opposed end plates defining a plurality of coplanar cylindrical chambers, said end plates having a plurality of ports, a sun component positioned in each chamber and operable upon actuation to roll planet components over the inner cylindrical surface of each chamber, the axis of each sun being permitted to revolve about a circular path eccentric to each chamber but intersecting the axis of each chamber so that as the eccentric position of each sun increases the barrier formed by each sun component and its associated planet components divides each chamber into progressively unequal portions, said ports being positioned as to supply hydraulic fluid to the portion increasing in volume and to discharge fluid from the portion decreasing in volume.

17. In a hydraulic pump or motor, the combination comprising a ring and opposed end plates defining a plurality of coplanar cylindrical chambers, said end plates having a plurality of spaced ports, a sun component positioned in each chamber and operable upon actuation to roll planet components over the inner cylindrical surface of each chamber, said components being provided with gear teeth and said cylindrical surface being provided with gear teeth adapted to mesh with the gear teeth of said components as to preclude slippage therebetween, means effective upon actuation to afford movement of the axis of each sun component about a circle eccentric with respect to each chamber so that the ports are covered by each planet when each sun is in an eccentric position and subsequent movement of each sun efiects uncovering of the ports so that some of said ports become intake ports and others of said ports become discharge ports.

18. A combined hydraulic pump and motor comprising a pump section including walls defining a cylindrical chamber, some of said walls having a plurality of ports, sun and planet components forming an epicyclic system with the inner cylindrical surface of the chamber wherein the sun and planet assembly forms a barrier dividing the chamber into two compartments, said sun component being operable upon actuation to roll the planet components over the said inner cylindrical surface, means for constraining said sun so that the axis thereof describes a circular path eccentric to said chamber but intersecting the axis of said chamber so that as the eccentricity of said sun increases the barrier formed by said epicyclic system varies said compartments volumetrically, said ports being positioned to supply hydraulic fluid to the compartment increasing in volume and to discharge fluid from the compartment decreasing in volume, and a motor section including walls defining a cylindrical chamber, some of said walls having a plurality of ports, sun and planet components forming an epicyclic system with the inner cylindrical surface of the motor chamber wherein the sun and planet assembly forms a barrier dividing the motor chamber into two compartments, said motor sun component being operable upon actuation to roll the motor planet components over the said inner cylindrical surface, means for constraining said motor sun so that the axis thereof describes a circular path eccentric to said motor chamber but intersecting the axis of said motor chamber so that as the eccentricity of said motor sun increases the barrier formed by said epicyclic system varies said motor compartments volumetrically, said motor ports being positioned to supply hydraulic fluid to the motor compartment increasing in volume and to discharge fluid from the motor compartment decreasing in volume, and passages connecting said pump section and said motor section whereby hydraulic fluid forced from said pump section actuates said motor section.

19. A combined hydraulic pump and motor comprising a pump section including a ring and opposed end plates defining a cylindrical chamber, said end plates further defining a plurality of spaced ports, a line joining said pair coinciding with a diameter of said chamber when said pump or motor is in neutral position and being spaced from said diameter when said pump or motor is in operative position, sun and planet components fenning an epicyclic system with'the inner cylindrical surface of the chamber wherein the sun and planet assembly 15 forms a barrier dividing the chamber into two compartments, said sun component, being operable upon actuation to roll the planet components over the said inner cylindrical surface, said components being provided with gear teeth and said cylindrical surface being provided with gear teeth adapted to mesh with the gear teeth of said components as to precludeslippage therebetween, means effective upon actuation to aflord revolution of the axis of said sun component about a circle eccentric with respect to said chamber so that the ports are covered by the planets when the sun is in an eccentric position and subsequent movement of the sun effects uncovering of the ports so that some of said ports become intake ports and the others of said ports become discharge ports, and a' motor section including a. ring and opposed end plates defining a cylindrical chamber, said end plates further defining a plurality of spaced ports, a line joining said pair coinciding with a diameter of said motor chamber when said pump or motor is a neutral position and being spaced from said diameter when said pump or motor is in operative position, sun and planet components forming an epicyclic system with theinner cylindrical surface of the motor chamber wherein the sun and planet assembly forms a barrier dividing the motor chamber into two compartments, said motor sun component being operable upon actuation to roll the motor planet componentsrover the said inner cylindrical surface, said motor components being provided with gear teeth and said cylindrical surface being provided with gear teeth adapted to mesh with the gear teeth of said motor components as to preclude slippage therebetween, means effective upon actuation to afford revolution of the axis of said motor sun component about a circle eccentric with respect 'to said motor chamber so that the motor ports are covered by the planets when the motor sun is in an eccentric position and subsequent movement of the motor sun effects uncovering of the motor ports so that some of said motor ports become intake ports and the others of said motor ports become discharge ports, passages connecting said pump section and said motor section whereby hydraulicfluid forced from said pump section actuates said motor section.

20. A combined hydraulic pump and motor comprising a pump section including a plurality of coplanar systems, each of said systems including walls defining a cylindrical chamber, some of said walls having a plurality of ports, sun and planet components forming an epicyclic system with the inner cylindrical surface of each chamber wherein the sun and planet assembly forms a barrier dividing each chamber into two compartments, the sun component in each chamber being operable upon actuation to roll the planet components over each inner cylindrical surface, means for constraining said suns so that the axis of each sun is permitted to travel about a circular path eccentric to its chamber but having one point intersecting the axis of said chamber so that as the eccentricity of each sun increases the barrier formed by said epicyclic assembly varies each compartment volumetrically, said ports being positioned to supply hydraulic fluid to the portion of each chamber increasing in volume and to discharge fluid from the portion of each chamber decreasing in volume, and a motor section including a plurality of coplanar systems, each of said systems including Walls defining a cylindrical chamber, some of said walls having a plurality of ports, sun and planet components forming an epicyclic system with the inner cylindrical surface of each chamber wherein the sun and planet assembly forms a barrier dividing each chamber into two compartments, the motor sun component in each chamber being operable upon actuation to roll the motor planet components over each inner cylindrical surface, means for constraining said motor suns so that the axis of each motor sun is permitted to travel about a circular path eccentric to its chamber but having one point intersecting the axis of each motor chamber so that as the eccentricity of each motor sun increases the barrier formed by said epicyclic assembly varies each motor compartment volumetrically, said motor ports being positioned to supply hydraulic fluid to the portion of each chamber increasing in volume and to discharge fluid from the portion of each chamber decreasing in volume, passages connecting said pump section and said motor section whereby hydraulic fluid forced from said pump section actuates said motor section.

References Cited in the file of this patent UNITED STATES PATENTS Whitmore Nov. 14, 1944 Grosser Dec. 28, 1948 Carrier Aug. 3, 1954 FOREIGN PATENTS Great Britain May 4, 1942 Germany Sept. 26, 1940 

